Blood vessels that have become enlarged and tortuous over a period of time are generally known as “varicose veins.” Most commonly, varicose veins occur in veins of the legs, and in particular, are most common in the superficial veins of the legs, although they can occur elsewhere. Varicose veins are caused when the leaflets of valves in the blood vessel no longer close properly, thereby allowing for retrograde flow and pooling of blood within the vein. Varicose veins are often painful and can produce ankle swelling, skin discoloration, dermatitis or venous eczema, cramps, and skin tightness around the affected region. In severe cases of varicose veins, complications may occur. For example, the varicose veins may become very painful and hinder a person's ability to walk. Further, skin conditions associated with varicose veins may also predispose a person to skin loss. Development of serious conditions like blood clots, carcinoma, or sarcoma, may also occur.
The traditional surgical treatment for varicose veins is “vein stripping” during which the affected vein is removed. Other non-surgical treatments include wearing elastic stockings, elevating the legs, and exercising. Another treatment is sclerotherapy.
Sclerotherapy is a treatment during which a sclerosing agent is injected into the varicose vein to cause shrinking of the vein. In order for sclerotherapy to be effective, it is necessary to evenly dispense the sclerosing agent throughout the wall of the vein without using toxic levels of the sclerosing agent. This is not particularly difficult for the smaller veins. However, it is quite difficult or nearly impossible in larger veins. When a larger vein is injected with a sclerosing agent, the sclerosing agent is quickly diluted by the large volume of blood in the vein. As a result, the vein is sclerosed only in the region of the injection. If the procedure is continued, and the injections are far apart, the vein can become disfigured. The problem cannot be cured by injecting a more potent solution of sclerosing agent, because the sclerosing agent may become toxic at such a concentration. Therefore, a need exists for a system that is capable of delivering a sclerosing agent to the varicose vein walls that prevents the dilution of the sclerosing agent into the blood and more evenly delivers the sclerosing agent to the wall of the vessel.